Dry cleaning machines and processes utilize a dry cleaning fluid which is normally a solvent, such as perchlorethylene. During the dry cleaning process a liquid waste stream is generated, known as separator waste water. This separator waste water is water with a small amount of entrained and dissolved solvent. The separator waste water is generated by the condensing process used in reclaiming solvent from washed garments during the drying phase of the dry cleaning process, and in condensing solvent vapor emitted by a solvent still.
Until the advent of regulations governing the disposal of the separator waste water, the separator waste water was poured down the drain. Now, the separator waste water is classified as a hazardous waste and environmental regulations prohibit the improper disposal of the liquid. Laws and regulations limit the amount of hazardous waste, such as dry cleaning solvents, that may be released onto the environment. Consequently, disposal of the separator waste water requires costly hazardous waste disposal procedures.
Systems that reclaim or recover solve from and/or decontaminate separator waste water are known in the art. U.S. Pat. No. 5,653,873 to Grossman describes a system and method for reducing liquid waste generated by dry cleaning. U.S. Pat. No. 5,236,580 to Kelleher describes a device for reclaiming dry cleaning solvents from a dry cleaning machine. U.S. Pat. No. 5,223,126 to Phillips describes a filtration system for decontaminating dry cleaning waste water, a thermal evaporation system for convert treated water into steam and a condenser to condense the steam back to water which is later disposed of. The Phillips device requires connection to a high voltage electrical source to power heating elements which evaporate the filtered water. This system would be subject to corrosion requiring the use of expensive corrosion resistant materials in the evaporation chamber. In addition, frequent replacement of expensive cartridge type filters would be necessary. Other systems include those disclosed in U.S. Pat. No. 4,354,363 to Holder and U.S. Pat. No. 4,513,590 to Fine.
Environmental considerations coupled with increasing disposal costs indicate a need for an efficient and effective system for reducing liquid waste generated by dry cleaning. In particular, it would be beneficial to provide an apparatus and method which would economically reduce the hazardous liquid waste.
Accordingly, it would be desirable to provide an apparatus and method which would economically reduce the liquid hazardous waste generated by the dry cleaning process by efficiently reclaiming the solvent from the separator waste water using an apparatus that does not require electrical power, heat or costly filter cartridges. This apparatus and method would purify the waste water into solvent, most of which could be recycled within the dry cleaning machine and highly purified water which may be safely and economically disposed of without harming the environment.